(expand_builtin): For fsqrt, always use the special insn, then test for nan.

In case of nan, set errno directly or call the library function.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@1586 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/expr.c b/gcc/expr.c
index 0682bca..e0a6a80 100644 (file)
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -4980,7 +4980,7 @@ expand_builtin (exp, target, subtarget, mode, ignore)
   tree fndecl = TREE_OPERAND (TREE_OPERAND (exp, 0), 0);
   tree arglist = TREE_OPERAND (exp, 1);
   rtx op0;
-  rtx lab1, lab2, insns;
+  rtx lab1, insns;
   enum machine_mode value_mode = TYPE_MODE (TREE_TYPE (exp));
 
   switch (DECL_FUNCTION_CODE (fndecl))
@@ -5015,39 +5015,10 @@ expand_builtin (exp, target, subtarget, mode, ignore)
       /* Make a suitable register to place result in.  */
       target = gen_reg_rtx (TYPE_MODE (TREE_TYPE (exp)));
 
-      /* Test the argument to make sure it is in the proper domain for
-        the sqrt function.  If it is not in the domain, branch to a 
-        library call.  */
       emit_queue ();
       start_sequence ();
-      lab1 = gen_label_rtx ();
-      lab2 = gen_label_rtx ();
 
-      /* By default check the arguments.  If flag_fast_math is turned on,
-        then assume sqrt will always be called with valid arguments. 
-        Note changing the test below from "> 0" to ">= 0" would cause
-        incorrect results when computing sqrt(-0.0).  */
-
-      if (! flag_fast_math) 
-       {
-         /* By checking op > 0 we are able to catch all of the
-             IEEE special cases with a single if conditional.  */
-          emit_cmp_insn (op0, CONST0_RTX (GET_MODE (op0)), GT, NULL_RTX,
-                        GET_MODE (op0), 0, 0);
-          emit_jump_insn (gen_bgt (lab1));
-
-          /* The argument was not in the domain; do this via library call.
-            Pop the arguments right away in case the call gets deleted. */
-         NO_DEFER_POP;
-          expand_call (exp, target, 0);
-         OK_DEFER_POP;
-
-          /* Branch around open coded version */
-          emit_jump_insn (gen_jump (lab2));
-       }
-
-      emit_label (lab1);
-      /* Arg is in the domain, compute sqrt, into TARGET. 
+      /* Compute sqrt into TARGET. 
         Set TARGET to wherever the result comes back.  */
       target = expand_unop (TYPE_MODE (TREE_TYPE (TREE_VALUE (arglist))),
                            sqrt_optab, op0, target, 0);
@@ -5060,8 +5031,45 @@ expand_builtin (exp, target, subtarget, mode, ignore)
          end_sequence ();
          break;
         }
-      emit_label (lab2);
 
+      /* Check the results by default.  But if flag_fast_math is turned on,
+        then assume sqrt will always be called with valid arguments.  */
+
+      if (! flag_fast_math)
+       {
+         /* Don't define the sqrt instructions
+            if your machine is not IEEE.  */
+         if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT)
+           abort ();
+
+         lab1 = gen_label_rtx ();
+
+         /* Test the result; if it is NaN, set errno=EDOM because
+            the argument was not in the domain.  */
+         emit_cmp_insn (target, target, EQ, 0, GET_MODE (target), 0, 0);
+         emit_jump_insn (gen_beq (lab1));
+
+#if TARGET_EDOM
+         {
+#ifdef GEN_ERRNO_RTX
+           rtx errno_rtx = GEN_ERRNO_RTX;
+#else
+           rtx errno_rtx
+             = gen_rtx (MEM, word_mode, gen_rtx (SYMBOL_REF, Pmode, "*errno"));
+#endif
+
+           emit_move_insn (errno_rtx, GEN_INT (TARGET_EDOM));
+         }
+#else
+         /* We can't set errno=EDOM directly; let the library call do it.
+            Pop the arguments right away in case the call gets deleted. */
+         NO_DEFER_POP;
+         expand_call (exp, target, 0);
+         OK_DEFER_POP;
+#endif
+
+         emit_label (lab1);
+       }
 
       /* Output the entire sequence. */
       insns = get_insns ();